Wall or ceiling construction



Dec. 11, 1934. K MACLEQD 1,984,028

WALL OR CEILING CONSTRUCTION Filed May 3, 1952 2 Sheets-Sheet l Dec. 11, 1934. K. MACLEOD WALL OR CEILING CONSTRUCTION Filed May 3, 1932 2 Sheets-Sheet 2 n n B n n u Ev Patented Dec. 11, 1934 UNITED. STATES PATENT OFFICE 1,9a4,oza

WALL on cnrmnc CONSTRUCTION Keith Macleod, Brookline, Mala, assignor to F. E. Berry Jr. 8; Co. Inc., Boston, Mass. a corporation of Massachusetts Application May a, 1932, Serial Not 608,877

8 Claims. (01. 72-118) The present invention relates to means for lin- Fig. 2a is a perspective view of a splice meming the rooms of buildings for various purposes, her or connector for the abutting hangers; such as absorbing and deadening sound, or ob- Fig. 3 is a fragmentary perspective view of one taining a desirable interior finish, in circumf the longitudinal y stances where it is impossible, non-feasible or F18. 4 is a perspective view of one 0! the transundesirable to apply the surfacing members diverse keys which is inserted between adjacent rectly to the walls or overhead closure of the tiles;

room. Its principles and main features are ap- 5 is e P rspective view of one of the clips plicable for lining all'the sides of the room, inr t rrup by whi h h h rs re connected cluding the ceiling as well as the upright walls. t0 the Suspenders; 10

The embodiment here illustrated shows the ap- 6 s a pe spective view of a key employed plication of the invention as a suspended ceiling, to support the dm t tiles, in its relation to but this is without intent of limitation to any O e 0! t e a e specific location or environment, or of excluding 7 is a fragmenta y Perspective View One 1,; use of the invention from any situation which 01 the y which maybe Used to pp One d involves the supporting or holding of tiles and 0f the endmost tile in each and Of all t e t like by engagement of their edges t t tiles in the row next to one of the walls of the holding means and without attachment by cement room; or nails t backing t t Figs. 8 and 9 are sectional views taken on The term "tiles" is used above, and in the follines d r pec e y 0 F lowing description, in a generic sense to include 10 is a sectioned w, n a Plane Parallel not only ceramic tiles (which may be mounted to the D of through t dmOst tile and set by the means of this invention), but the row next to One e Of t room; also slabs or boards of other materials, and in- 8- 11 is 8 fragmentary sect o al View on a eluding acoustical tiles, so called, of material and plane parallel o a 0 9 th ou h e endconstruction which are largely absorptive of sound most tile in 8 vibrations. Such tiles may have any dimensions 12 s a S c na View On 8- pla e parallel to and are preferably rectangular, although their a the same p through a tile peripheral form is not important provided it en- 0f the row next to the pp Wa f the oom ables the tiles to be matched together and aiTords from that shown in Fig. 1 straight sides to receive the keys by which they 13 s De De Ve e showing a o m are im d 1 1 d, of suspender and hanger clip adapted to be at- The invention comprises hangers which may be tached directly to a wooden floor beam or rafter suspended from an overhead support or mounted for suspending a Ceiling therefrom; to extend from, or form part of, a wall construc- 14 shows the same form of suspender tion, and keys, both associated with, and indethat in 8- 13 bolted to the web of a steel floor pendent of, such hangers directly engaging the i tiles and occupying grooves between their front 15 1s a Perspectlve showmg an alteranrl back faces. The invention further includes Fatwa form of suspender adapted to be embeeded m provisions by which the hangers may be com in aconcrete floor or roof andtobe bent atagiven 4 nected adjustably with suspension means or fofssilpportmg gt f i gg structural parts of the building. The illustration perspec We 5 e furnished herewith shows the specific embodipender of 15 thus bent up and engaged with the clip, together with an alternative form of ment of the invention in a ceiling composed of hanger. acoustical tiles with a. variety of suspension Fig i is a perspective View of a clip adapted means for the F hangers; to engage the lower flanges of an I-beam for sup- In the drawings which illustrate this embodiporting an alternative suspender; Fig. 18 is a perspective view of a suspender of Fi 1 i a perspective View as seen from the type adapted to be held by the clip shown in neath, of the ceiling referred to, partly broken Fi 17; away to show the suspension structure, which is Fig. 19 is a fragmentary perspective view showconcealed by the tiles of the completed ceiling; ing the clip and suspender last described assem- Fig. 2 is a fragmentary perspective view of one bled with an I-beam and a tile hanger; of the tile hangers; Fig. 20 is a cross section on line 20-20 of Fig. 55

2 19 showing in addition the adjusting and locking nuts for the suspender and a key for the adjusting nutturnedup into holding position;

Fig. 21 is a view similar to Fig. 20, showing a modiflcation of the clip last described for use with an angle or channel bar.

Like reference characters designate the same parts wherever they occur in all the figures.

The ceiling construction shown in Figs. 1-12 inclusive comprises square tiles 22, hangers 23, suspenders consisting of wire loops 24 and channel irons 25, clips 26, longitudinal keys 27, and transverse keys 28. The tiles are of substantial thickness, being made, in this illustration, of'the material and construction known commercially as acousti-celotex. They have deep grooves 29 in each of their four sides, any desired distance from the top or bottom surface, but all at the .same distance from one of the surfaces. That is, the ledges which form the upper boundaries of all the grooves are in the same plane.

This ceiling is shown as suspended from a conorete upper floor. The wires of the hanger loop may be embedded in the concrete floor at the time of casting the floor, and may be arranged to surround reinforcement members of the floor, or they may be attached to hooks or sockets embedded in the concrete. It is the usual practice in constructing buildings with reinforced concrete floors to provide protruding wires, or hooks exposed on the under side of the floor, for supporting anything which it may be desired to suspend beneath the floor, wherefore the provision of hanger loops of the kind here shown involves no new step or departure from standard building practice. The wires are brought around opposite sides of the channel bar 25 and twisted together under the bar to form the loop; the channel bar being long enough, (it may be as long as the width or length dimension of the room) to be thus engaged by a number of such hanger loops of an alined series. Other bars are similarly hung, parallel or. approximately so, to the two bars 25 shown in the drawings. All of the bars are adjusted to a common level by shortening or raising the individual loops as needed. This is readily done by twisting the wires together by a toggle rod 30', as shown in Fig. 1. I have adopted the term suspenders, or suspension structure, to designate the parts last described, and to distinguish them descriptively from the hangers which depend from them and directly engage the ceiling tiles.

The hangers 23 (so called for descriptive purposes without limiting intent) are made each from a long and straight strip of sufliciently stiflf metal, as galvanized sheet iron, with a lateral flange 31 at one edge, and a lateral bead or fin 32 at the other edge. Such flange and bead may extend both to the same side of the hanger, or to opposite sides. Preferably they extend to opposite sides, but in the case of the hanger which comes next to one of the walls of the room to support the outermost row of tiles, the flange and bead should both project away from the wall in order that the hanger may be fastened to the suspension structure and that the outer edges of the tiles may come flush with the wall. The flange 31 is preferably corrugated to provide parallel upward ridges 33 and 34 for engagement at separated points with the under sides of the suspender bars or channel irons 25, and an intermediate down-. ward rike' 35 for engagement stably with the clip 26. The outer edge 36 may, but not necessarily, be extended and bent down, as shown, to

- stifl'en the ridge 34 and avoid the occurrence of a raw edgealong the line of this ridge. The bead 32 is formed by bending outward and doub-' ling back one edge zone of the strip out of which the hanger is made, with an intermediate space forming a channel 3'? for reception of the longitudinal keys 27. While the above described mate- I rial and mode of fabrication ofgthe hanger are of advantage in that the hanger? may be so made without special machinery and equipment, and are claimed as a secondary feature of the invention, nevertheless they are not limiting factors of the generic invention. The fundamental principles may be contained in hangers of other forms,

as will be later. described. They are made of substantial length-convenient for shipment and installation. They may be shortened by cutting, to fit a room of small dimensions, or assembled in line with other hangers in a large room, and

spliced together by fish-plates or connectors overlapping their abutting ends. A suitable connector for this purpose is shown in Fig. 2a and designated 371. It is adapted to overlie the lateral flange of the hanger and has a web 3'72 at one side to embrace the intermediate part of the hanger, and a curled under lip 3'73 at the other side to embrace the edge of such flange.

The clips 26 are each made of a piece of heavy iron wire so bent as to form a loop 38 to overlie the channel bar 25, and two hooks 39 and 40 to underlie the corrugated flange 31 of the hanger and to engage the downward ridge 35 of the latter.

the clip symmetrical on opposite sides of the channel bar, with the hooks 39 and 40 approximately equidistant therefrom, I pre'ferto elongate the part bearing one of the hooks, as 40, making a long and resilient arm 41 for faciliity in applying the clip manually. It will be understood that when the clip is in unstressed position the dis-- tance of the loop 38 from the line joining the hooks 39 and 40 is less than the combined depth of the channel bar 25 and downward ridge 35,, whereby the clip must be flexed and strained (but only within its elastic limit) in being applied, whereupon it then holds the hanger forcibly against the channel bar. It may be well to note before going further with the description that I have, for present convenience, designated as the longitudinal sides of the tile, those sides which extend along the hangers 23, and as transverse, the sides which extend across from, one hanger to the next; this regardless of the relative lengths of these sides. It is convenient .to consider as longitudinal, those sides which extend lengthwise of the rows of tiles between hangers. Corre-' spondingly I have called the keys 27, which interconnect with the hangerathe longitudinal keys, and those which enter between the edges of adjacent tiles in the same row, the transverse keys.

The longitudinal keys are preferably made of equal length with the tiles, although they may be several times this length, and have a lip or flange 42 along one edge adapted to enter andflt rows may be supported in exactly the same plane. Conveniently the longitudinal key is made of a strip of sheet metal, thus ofl'set along a line at the proper distance from one edge, and its other edge is doubled back on the under side (with respect to the position in which the key is shown inthese drawings) and in such a position that its outer surface is oflset equally from the underside of the locking fln 42. This enables the key to be used either side up with equal eflect. The rolled over flange is cut all a short distance back from one end of the key, as shown at 44 in Fig.3; or it may be thus cut ed at both ends, or-the ofl'settop part of the key may be correspondingly cut away, in order to provide a tab of reduced thickness for overlap or underlap with acorresponding tab .on the end of the next adjacent transverse key, in order to extend across the joint where the corners of adjacent tiles come together. Suchoverlaps of the keys prevent flow of air, or :breathing, as it is called, between the room and the space above the ceiling w.-th changes of temperature and atmospheric pressure. Such air flow, although inconsiderable, leaves a depositof:dirt around the openings through which it passes, and in time causes the spots so affected to 'app'ear-soiled in contrast with the rest of the tile surfaces. Such breath'ng and discoloration is' prevented throughout the entire extent of the joints'between contiguous tiles. Throughout the major part oithese joints it is prevented by the beads and. flanges of the hangers and keys, extending deeply into the edge grooves of the tiles, as shown by-Figs. 8 and 9. The deep penetration of such beads and flanges makes the only course. through which air can flow a long and tortuous one, whle theirengagement with either the, top or bottom groove-bounding ledges of the tiles, substantially blocks these tortuous passages.

'7 The key overlaps above mentioned, and further touchedv upon, eliminates also such breathing openings as would be left if the keys abutted against oneanother at their ends.

The intermediate key 28 has opposite flanges or beads 45,46, and an upright longitud'nal web in-"the middle. The beads enter equally, or substantially or nearly so, into the grooves of the transverse edges of two adjacent tiles. These keys may also be made of sheet metal bent and folded on longitudinal lines into the form shown, with their beads of a depth substantially equal to .the width of the receivng grooves in the tiles, whereby to assist in alining the tiles in a given plane. The beads may be cut away at the top side, as shown at 47 in Fig. 4, or at the under side, to facilitate the corner overlap just described, and an overlap or underlap wth the beads of the hangers.

Instead of making the keys of folded sheet metal, they may be rolled out of solid bar stock with diflerent thicknesses in difierent parts, substantially of the order indicated for the sheet metal structures.

It will be noted that when the longitudinal keys are assembled with the hangers as described, they constitute in effect a bead or fin projecting from the opposite side of the hanger to the inte gral head 32 of the hanger. That is, the hanger then is-possessed of keys (the bead 32 being essen- --tially a key) interlocked with tiles at opposite sides. This feature of the invention may indeed be embodied in a hanger of rolled construction with integral flanges like those of an I-beam to serve'as-a key,and with corresponding flanges in -placeof the corrugated flange 31 to interlock with a clip. Such alternative form: 01- hanger is shown in Fig. 16 in association with an alternative form of clip, later described in detail. I wish toemphasize at this point that the tile engaging keys at opposite s'des of the hanger may both be inte-gral with the hanger or one of them may be detachable, within the scope of the invention as claimed.

The method of suspending a ceiling by the means here described is as follows. The channel bars 25 having been suspended and leveled, hangers are fastened up against them from beneath by the clips 26 and spaced apart approximately equal to the width of the tiles. Preferably they are arranged symmetrically with respect to the room, that is, with the middle two hangers equidistant, on opposite sides, from the middle line of the room, so that if the dimension of the room is not equal to a whole number of tiles, the tiles may be cut so that the two outermost rows will have the same width. Tiles are first inserted between the two middle hangers, beginning ordinarily at one end of the intermediate space, being first engaged with the integral flange or bead of one hanger and then locked with the other by insertion of a longitudinal key. Transverse keys are inserted between successive tiles of the row. Other rows are similarly set on each side of the middle row until the walls of the room are reached. If

necessary, in order to bring the tiles of adjacent rows close together, the hangers may be moved laterally without disconnecting their holding clips from the bars of the suspension structure,

for the clips bind the hangers with a light enough i pressure to enable them to be thus moved by exertion of a moderate thrust or taps of a. hammer.

The key shown in Figs. 6 and 11 serves for supporting the outer ends of the endmost tile of a row. It extends crosswise of the hanger and has a bead or key flange 49 entering a notch 50 in the end of the hanger. Such a key may extend in one piece across all, or any lesser num-- ber, of the hangers in a room, or separate keys may be spliced together. The key has a web 51 adapted to lie close to the wall 52 of the room, and from which tongues 53 are struck out so as to underlie a shoulder 54 in the edge of the tile. The tongues are inclined upwardly and away from the wall to permit passing of the shoulder,

and to spring out beneath the shoulder. Of course the ends of the tongues are so related to the under side of the bead, to the lower boundary of the notch 50, and to the depth of shoulder 54,

as to support the tile with its under face in the correct plane.

Another form of key for holding one longitudinal side of the last tile to be placed in any row, and correspondingly with all of the tiles of an outermost row, is shown in Figs. 7, 10 and 12. This key has a flange 56 to enter the channel of theadjacent hanger, a rising part from which tongues 57 are struck back similarly to the tongues 53, to engage the edge of the tile or a shoulder 58 therein similar to shoulder 54, and a flange 59 to overlie the top face of the tile and prevent it from being pushed up too high. Such a key is needed with all the tiles of a row only when the hanger between that row and the wall is situated as in Fig. 12; that is, with, its head extending toward the wall The tiles of that row are cut back to leave a flange 22a extending out to the wall 60. By using the special key it becomes unnecessary to weaken such flange by cut-.

ting a groove still further back to receive the normal type key 27.. Tilea-not only those made of soft material like celotex, but also ceramic tiles and others of more or less hard material, may be cut by suitable tools to flt. the dimensions, and irregularities of outline, ofany room.

In order to position the endmost 'tiles of the intermediate rows and the endmost tile of the last row, the portion of the longitudinal edge of the tile which normally would rest above the bead 32 or that portion which normally would rest above the projecting portion of the last transverse key 28 in these rows may be cut away. The last tile in a row will then have one edge cut away as above mentioned, one edge grooved, as shown at the left of Fig. 10, to receive either the bead 32 or the transverse key 28, one edge formed with the shoulder 54, as shown in Fig. 11, and one edge formed with the shoulder 58, as shown in Fig. 12. The tile can be positioned by fitting either the bead 32 or the key 28 in the groove and snapping the shoulders 54 and 58 by the tongues 53 and 57 respectively. If desired, a special key similar to that shown in Fig. 7 could be used in place of the last transverse key 28.

It is not necessary that the grooves in the sides of the tiles be exactly the same depth as the beads of the hangers in the outstanding flanges of the longitudinal keys, but preferable rather that they be of somewhat greater depth so that the channel'walls of the-hangermay spread slightly in receiving a key, if necessary,

and to permit easy insertion of the key, without dange r of splitting or breaking the tile, particularlgif it is of brittle material.

The foregoing description of method is the preferred one followed with the use of separate insertable keys for one side of the hanger, but it does not exclude the use of a hanger such as that designated 23a in Fig. 16 having integral keys 32a and 43a at opposite .sides of one edge. When hangers of this alternative design'are used, they may be initially placed with a divergence between them wide enough at one end to admit the tiles flatwise between the keys of adjacent hangers; which tiles, after being interengaged with the keys, are slipped toward the narrower end of the intermediate space. When all the tiles have been inserted, the hangers may be adjusted into parallelism, or other prescribed final relationship, as previouslyv described. Each successive row of tiles may thus be inserted between a properly placed hanger and one tempo-- rarily set sufllciently askew for the purpose. Or the integral keys may be cut away or interrupted on one side of the hanger for a long enough distance to permit the insertion of tiles without spreading the hangers apart.

An alternative suspender adapted for application to wooden floor and roof beams or rafters is shown in Fig. 13. It consists of a plate 61 having holes 62 for the reception of nails. The lower edge of the plate is turned up toprovide a hook-like lip 63 for interengagement with a down turned complemental lip 64 on a clip 65. Such plate suspenders are nailed to the sides of rafters at a distance apart in one direction approximately equal to the required spacing of the hangers 23, and with any suitable spacing in the transverse direction. They are set at heights which will locate the tiles of the ceiling in the described, lend themselves to the construction of barrel ceilings, where the hangers extend lengthwise of the arch. The clips 65 have notches 66 suitably shaped to receive the upper flange and part of the web of any of the hangers. Where the hanger is of I-beam form,-with.two locating flanges 31a and 31b, shown in 16, the notch is T shaped, but the corresponding notch for hangers of the kind flrstdescribed is angular. The clip is slidable in one direction on the flange 63 of the suspender,"and--in-a" transverse direction on the hanger, which gives complete facility for adjustment of the hangers to enable the tiles to be properly abutted together. 1

The same type of suspender platelast described may be fastened to metal rafters 67.12!

T or angle shape,'that is, a shapeiwhich'proe vides a vertical web without base flanges.- It is secured to the rafter by bolts passed through holes drilled in the rafter at the required height, and at distances from holes prepared forvother suspenders suitable to the character --.of-..-. the ceiling. f

Figs. 15 and 16 illustrate another form of suspender adapted to be embedded in a concrete. floor or roof and to project belowr-thez-under, surface of such floor or roof. These suspenders designated 68, being located, when the concrete is cast, in rows appropriate .to the prescribed arrangement of tile hangers,.'are marked -.for. bending up on lines, indicated at 69 in Fig.=-15,- or diflerent levels appropriate to the contour'of the ceiling, and are bent up onthe lines indicated, passed through slots 70 in hanger plates '71, and further bent up to secure the plates. The plate 71 is formed with a turned up hook flange '72, similar to the flange or lip 63, for interengagement with a clip 65 like: that last described. The suspender 68 and plate 71.:to-: gether constitute a composite suspension structure which, together with the clip 65, permits adjustment of the hanger in all directions. -;'I-he plate '11 also has holes 73 which enable it to be suspended by wires embedded in the concrete floor, like the wires of the loop. 24, instead of by a strap member as 68. This capacity.for bending of the strap suspenders 68,-.and equivalent wire suspenders, at any level, enables the hangers to be readily hung at the required level and to be equally supported at its various points of suspension. I

For suspending the tile hangers from rafters or beams of I-beam section, I have provided clips 74 and suspenders 75 (Figs. 17-20).; The, clips are formed with inturned lips 1'75 and. .76, adapted to embrace and overlie the flanges at the base of an I-beam 77 and with enough greater width than such flanges to permitof the lip '16 being first slipped over one flange.

and moved back until the lip can pass over the opposite flange. Then the clip is withdrawn to the position shown in Figs. 19 and 20, and locked there by the suspender 75. ..Such suspender has a screw threaded shank whichmayy be entered into an open notch 78 in one side embrace the top'flange 31 of the hanger. A nut 81 to adjust the height of the suspender is screwed on its shank above the clip, and a 1.061;. nut 82 is placed on the shank below the. clip,

The nuts are screwed on the suspender, and

, prevented from coming'off by upsetting the end of the shank, and the adjusting nut 81 is screwed back as far as possible before the suspender is located in the clip. After the correct height adjustment has been made, the adjusting nut may be secured by turning up a tab 83 on the outer side of tongue 79, as shown by Fig. 20. This suspender may be turned about the axis of its shank to accommodate hangers running in any direction with respect to the beam 7'1 and to permit mounting of the hanger with its tile engaging bead projecting to either-side.

The modification of this last design, applicable to angle or channel irons, differs in that the clip 74a lacks the horizontal lip 175 of clip 74, and the upright web 84 is arranged to lie close against the back of the upright web of the angle or channel iron 85.

Application of the invention to form upright walls, or an inner lining or facing for walls, is made in essentially the same way as before described except that the beams or bars 25 are set to conform with a wall instead of a floor. They may be thus set vertically side by side, or horizontally one above another. They may be placed alongside an already complete wall, spaced apart from it far enough to admit the clips 26, or serve as the skeleton of a wall. The hangers are attached to them by clips as described, to run horizontally if the bars are vertical, or vertically if the bars are horizontal, or may be inclined if necessary. With such variation in direction, the wall construction is substantially identical with the illustrations in Figs. 1-12 inclusive and the foregoing description, tiles proceeds in essentially the same way. So also may the clips and suspenders of Figs. 17-21 be used to attach hangers to structural beams of a wall or to flanges projecting from a wall. With this explanation, it will be understood that the term hangeri, and terms indicating direction and position with respect to the horizontal and vertical, used in the foregoing detailed descrip tion, have no significance as limiting the scope of the protection which I claim, but are merely convenient terms of description.

This invention, in all its illustrative embodiments, provides a very flexible, and yet absolutely secure, support for the facing tiles, which enables them to be set flush with one another and with complete concealment of the holding means. Although this illustration shows the tiles as beveled on the edges, this is not an essential feature and they may be made with square edges and set with very inconspicuous joints. At the same time the whole structure may be assembled, and the tiles set in place, with great ease and very rapidly. The ceiling or wall facing so made may be of a sound deadening character or not, as desired, according to the nature of the tiles selected, and it may be plain or have any desired quality of ornamentation. Square or rectangular outline of the tiles is not obligatory, since they may have any other polygonal forms which will match together; and the hangers need not neces, sarily be parallel to one another, although genand the mode of laying the erally it is preferable that they should be. A very low cost of installation is possible with this invention.

What I claim and desire Patent is:

1. A ceiling or wall structure comprising hangers having a tile supporting bead or flange projecting to one side and a key receiving channel opening towards the opposite side, a key removably inserted into said channel to project to the opposite side of the hanger from the bead, and tiles at opposite sides of the hanger having grooves in their edges between their faces adapted to receive said bead and the projecting portion of said key.

2. A structure as set forth in claim 1 in which the tile-positioning faces of said bead and said key are in the same plane.

3. A construction as set forth in claim 1 in which the hangers extend throughout the length of a plurality of tiles in a row and position all the tiles of such row, while the removable keys are of substantially equal length to the tiles.

4. A construction as set forth in claim 1 in which the hangers extend throughout the length of a plurality of tiles in a row and position all the tiles of such row, while the removable keys are of substantially equal length to the tiles and are placed each with its major part in one tile and have a projecting end overlapping the joint with the next tile of the row.

5. A construction as set forth in claim 1 comprising further removable transverse keys between contiguous tiles 'of a longitudinal row of tiles engaging both of such contiguous tiles.

6. A construction as set forth in claim 1 comprising further removable transverse keys between contiguous tiles of a longitudinal row of tiles engaging both of such contiguous tiles, the transverse and longitudinal keys being extended to overlap at their contiguous ends.

'1. In a ceiling or wall construction, the combination with tiles arranged in rows, of hangers between the rows of tiles having a lateral flange on one side interlocking with the adjacent parts to secure by Letters .of the tiles on that side, and a channel opening toward the other side, keys occupying said channel and projecting toward the other side of the hanger into locking engagement with tiles of the adjacent row, and a key for the endmost tile of a row having a flange overlying the outer face of the tile, 9. portion beside the adjacent side of the tile, and offset tongues interlocking with a shoulder at the adjacent side of the tile.

8. In a ceiling, hangers spaced apart and adapted to receive a row of tiles between them, one hanger having a bead or flange projecting toward the second hanger for engaging and supporting such tiles, and the second hanger having a channel opening toward the first mentioned hanger, and a tile-supporting key having a flange contained in said channel and a rising part provided with a catch inclined upwardly away from the contiguous hanger to underlie and support an overlapping shoulder on the tile. 

